DESCRIPTION The goal of the project is to evaluate antibody and cell-mediated immune responses induced in stage IIB ad III resected melanoma patients vaccinated with KLH-conjugated GM2 ganglioside with QS-21 (GMK) or treated with standard IFN alfa-2b. The work proposed constitutes the immunological monitoring component of an ongoing Phase III clinical trial (E1694). The hypothesis to be tested is that immunization against GM2 induces anti-tumor IgG and IgM and T cell responses that may be of therapeutic benefit. The investigator plans to evaluate antibody responses, cytotoxic and cytokine-productive responses and signal transduction defects of peripheral blood lymphocytes obtained from melanoma patients. Host immune responses will be correlated with disease outcome (disease free interval or overall survival) in order to assess the relative anti-tumor roles of humoral and cellular immunity.